Do you use parking brake?

Amen to that ... before Toyota did the steering rack warranty enhancement work on my Gen 1, it had reached a stage where, only on a long enough road trip, the steering ECU would count enough glitches to say "ok, I'm done" and discontinue assist. Usually that would be in the middle of a long stretch on highway, it did not light a warning light (possibly a 2001 bug, that), and I wouldn't even notice until the next exit I had to take. Then I'd come unsuspectingly to a stop at the end of the ramp, try to turn onto the crossing road, and have to throw both arms and shoulders into it....

-Chap

 

I learned to drive when I was 4 years old on a 1972 Capri without power steering. I remember struggling to turn the wheel for 90 degree corners, but even then I could do it (barely). Yes, cars without power steering are designed for that, but the forces aren't as different as the strength of my arms from then to now.

 

I was 32 before I owned a vehicle with power steering. Compared to the cars I drove then, though, a Prius has both a heavy front and a steering ratio that is definitely chosen with the power assist in mind. When the assist was out, I actually sort of preferred the feeling at speed ... when I could notice the difference at all, it just felt a little ... tighter. Quite nice. As for slow maneuvers and parallel parking ... manageable, yes, but enough work to cause lapses in conversation.

-Chap

 

Steering without assist possible, but the hypothetical is an emergency situation that has lost brakes and electrical power. The point is that in order to have a scenario in which a manual parking brake bests an electronic one in an emergency means having multiple other problems to deal with.

 

Here's a couple of pictures of my Austin Champ (ex. Army ¼-ton truck) which I drove when I lived in the UK (early 1970s) - power-steering? …dream on! After driving "Grond" for a couple of years my upper-body, arms, and biceps were in the best condition they've ever been in!!! Check out the size of that steering-wheel!

 

A big vehicle without assist is a DC3, which can weigh 25,000 pounds.

 

I think the steering gear on a plane is operated through the rudder controls. So you use your feet to steer a DC3.

 

Many larger planes have a "tiller" which is a small steering wheel to control the nose gear. The DC3 has a free-castering tail wheel so you control your steering on the ground with rudder pedals and/or differential braking (also on the pedals). All three surfaces - rudder, ailerons, elevator - are manual only. Stories are that the plane can wear you out if you aren't in great upper-body shape and, in fact, it's common for the copilot and pilot to trade off flying ("pilot in command") duties to give each other a rest, not just for a mental break but for a physical one as well. 25,000 pounds is a lot of plane to throw around the sky on the forces of your arms against the control surfaces.

 

In the air steering is done by a combination of aileron and rudder. In passenger aircraft the aileron is controlled by the yoke, aka control wheel. In theory you could turn an airplane with just the rudder, but that would be like a race car making a turn at high speed on a non-banked track. One way to think of it is that the aileron creates the equivalent of a banked track for the airplane while turning. In fact its referred to as "banking" the plane.

We can thank the Wright brothers for figuring out that you need to bank a plane while turning. And we can thank Donald Douglas for the DC-3, probably the greatest airplane ever made.

And with no autopilot!

 

All DC-3's have a voice activated autopilot, and always have. It's the person in the seat next to you.

 

Possibly someone has already noted this... but, growing up and living in a city where most on-street parking is in parallel parking spaces with someone parked behind and in front, it's very likely that one's car will get "nudged" forward or back. Getting the bumpers scraped up is bad enough, but having damage done to the drive train is much worse. With the mechanical brake set, the car might skid an inch or two on its non-rotating tires, but the drive train's parking pawl won't be sheared off or other damage done to gears or rotating parts. That, primarily, is the reason I am in the habit of always setting the parking brake.

(I did live in San Francisco for a dozen years where I learned the legally-required habit of curbing my wheels when parked on a non-level surface. It's also not a bad habit to have, even in the relatively flat east-coast city where I live now.)

 

I don't see how that would do anything unless you found a way to NOT set the parking pawl (which I'm sure you didn't). The load on the pawl will be the same regardless of whether the parking brake is set or not, assuming the car is moved the same amount.

 

In the case of a Prius (or other FWD car) Lee Jay has a point, given that the wheels braked by the parking brake are not the same wheels involved with the parking pawl. The protective effect would be greater in a RWD car.

Not to completely write off the protective effect even with FWD ... yes, the load on the pawl will be the same "assuming the car is moved the same amount" ... but if you compare collisions of equal energy (instead of collisions that move the car the same amount), the car with the brake set will not move the same amount as the one without, so that assumption won't apply.

With any luck, you won't get nudged hard enough to bust the parking pawl; harking back to the federal standards mentioned in post 154, it ought to stand up to at least a 2½ mph front or rear impact, which doesn't sound like a lot, but in parallel parking that'd be quite the "nudge".

-Chap

 

sorry for the comparison but a Yaris has self adjusting rear brake/parking brake "system", why wouldn't the prius?

 

My Prime rolls quite a bit if I don’t use the parking brake. I have started using it because of that.

 

I always set the parking brake if there's a higher than normal chance of my car getting towed. Not as much of a concern on the Prius, but a big concern for my full-time 4wd 4runner. Just the other day I saw a Jeep being towed with the rear wheels on the ground. The front wheels were spinning full speed, rubbing against the part of the tow truck that was holding it, and making a huge cloud of burnt rubber smoke. I hope the towing company is paying for a new set of tires for the owner.

 

Compared to other cars with automatic/CV transmissions, the gap between the park pawls on the Prius seems larger than others and this lets the car roll a bit more. To avoid shock to the drivetrain, you can put the car in park and slowly release the brakes to let the car slowly and smoothly engage the park pawl. Once it’s on the park pawl there is no further shock.

The parking pawls are shown in this video at about the 2 minute point.

 

Forget tires. I hope they are paying for a new drive train.
Saw a tow truck with a FWD minivan that had the front wheels on the ground. Few miles up the road, the truck was pulled over with smoke billowing out of the van.

 

Very much appreciate this forum chat... I'm actually trying to "brake" my habit b/c I often find myself backing out in reverse which goes quite swell, until a feel a few jerks and realize the brake is on... no more of this for me.. I needed a reason to "brake the habit"...

 

No, unless on a steep incline/decline.